There’s something special about film. At least before the advent of digital technology, cinema was for the most part an art of the real. True, there was animation, which gave free rein to the imaginary in much the same way as CGI does now. But otherwise, no matter how much it has leaned towards escapism, film has been married, for better or worse, to material reality. It records the existence of surfaces.

Now, that may not take us very far if we’re looking for a detailed or exact representation of thoughts, feelings or the workings of what some call ‘the soul’, let alone a precise delineation of the abstract forces at work in society or the universe. But in the right hands film can still achieve a lot. Think Ingmar Bergman, Carl Dreyer, Éric Rohmer or Buster Keaton, all of whom displayed great expertise in dealing with the inner lives of individuals; think Fritz Lang, Ken Loach, Francesco Rosi or the Rays (yes, both Nick and Satyajit) in terms of the external forces that may shape us.

The Innocents (1961)

Film can be perfectly eloquent when it comes to exploring such subjects – just as long as the filmmakers are adept at the art of suggestion. The camera, after all, is basically restricted to showing what is visible.

Which may make it a little surprising that so many films have been concerned with the supernatural. Sound helps no end, of course. If you have a scene where things unseen go bump in the night, the discrepancy – indeed, the tension – between what’s seen and what’s heard provides a great opportunity for the creation of mystery and suspense. We inevitably ask ourselves what’s making the noise and why, and what the noises signify in terms of what’s about to happen.

Filmmakers too have to ask themselves a very basic question: ‘to show or not to show’. That’s always been a matter of crucial importance to anyone wishing to arouse anxiety or fear (or, indeed, desire) in the spectator. Famously, the producer Val Lewton – the mastermind behind such unsettling movies as Cat People (1942), I Walked with a Zombie, The Leopard Man and The Seventh Victim (all 1943) – generally felt it was best not to reveal too much, and I have to confess I’m generally in agreement with him. However expert and inventive an art director, a costume designer or a makeup artist, it’s unlikely they can produce anything as plausible or scary as whatever fetches up in an individual’s imagination.

Most of the greatest directors understand this, and know that it’s better to have the audience engage actively and imaginatively with a movie than it is simply to spoon-feed them every morsel of the narrative and expect them, passively, to swallow them whole.

The Innocents (1961)

Which brings me – a little belatedly, I confess – to the point I wanted to make, or at least to the film I wanted to make the point about: Jack Clayton’s The Innocents (1961), which the BFI is reviving as part of its Gothic project. It’s widely and, I think, rightly regarded as one of the finest cinematic ghost stories as well as one of the scariest, and that’s not just because it’s an adaptation of one of the greatest ghost stories ever written: Henry James’s The Turn of the Screw. Quite simply, it’s a terrific piece of cinematic craftsmanship, with both its dramatic power and its richness of meaning enhanced by the script, the performances, the location and sets, the camerawork, lighting and editing, and the sound.

I’m not giving too much away by saying this, but it’s interesting to note that Clayton and his partners in creation (including Truman Capote, probably responsible for the wonderful subtlety and precision of the dialogue) chose to negotiate a tricky midway course between the show-everything and show-nothing options. In short, though we don’t always see ghostly presences (even when we are hearing things which suggest their presence), there are times when we see… well, we’re not quite sure what it is that we’re seeing, not quite sure whether it’s real or imagined.

The Innocents (1961)

And therein lies the film’s effectiveness. The key to The Innocents’ success as a psychological thriller is a carefully sustained and extremely haunting ambiguity which is reflected in the title itself: who, really, is innocent here? The young orphans committed by their uncaring, absent uncle to the charge of a new governess? The kindly but not especially bright housekeeper, who has kept an eye on them in recent months? Or the governess herself, who comes to suspect that the children have somehow been corrupted by her late predecessor and her lover? Deborah Kerr’s lead performance, certainly, succeeds on so many levels that we are never quite sure how innocent she may be. But then that leads on to more questions.

If we are referring to ‘innocents’, we need then to ask of what, exactly, they are supposed to be innocent? Knowledge? Sin? Something else? That, I’d suggest, remains to be seen.